narrator: los angeles county is beginning to develop ways to reduce the infrastructure's impact upon the environment. on the front lines of protecting the beaches, are the crews that clean out the stormwater system. man: this big vactor truck works on the same principle as your vacuum cleaner in your house, only this thing sucks up the whole house. some of the storm drains collect a lot of trash. i started cleaning drains in '93. they were horrible because they hadn't been maintained so much. now this is a priority. you have trash, animal waste, and it ends up on our beaches. that is a health risk. that is one of the main reasons why we have to close the beaches after heavy rain. narrator: but even when it's not raining, water still enters the stormwater system, carrying pollutants. here on the west coast, a lot of our storm drain systems are separate from the sanitary sewer system, so if you dump something in the storm drain, it goes right to the ocean untreated. alamillo: we haven't had a major rainstorm in the last year or so yet there's a lot of water in this creek here. i would say 20% of it is